Knee brace



FIG. 1 is a perspective view of a knee brace, showing my new design;

FIG. 2 is a front view;

FIG. 3 is a rear view;

FIG. 4 is a left side view;

FIG. 5 is a right side view;

FIG. 6 is a top view; and,

FIG. 7 is a bottom view.

The broken line showing of the securing straps in the views is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a knee brace, as shown and described. 